The "TermSrv_API_service" is a Remote Procedure Call (RPC) service that is available on some versions of Microsoft Windows. It stands for "Terminal Services API"
The TermSrv_API_service provides an API for applications to query and manipulate sessions on the Windows Terminal Server. It is typically used to manage Remote Desktop Services sessions.
The TermSrv_API_service can be used to perform a variety of tasks related to sessions, such as:
Session Management: The service can be used to query the status of sessions, log off users, and disconnect sessions.
Remote Desktop Connections: Applications can use the service to connect to the Terminal Server and create new remote desktop sessions, or to query the status of existing sessions.
Remote Control: Applications can use the service to remotely control other sessions on the Terminal Server, allowing them to send keystrokes, mouse movements, and other input to the remote session.
Remote Application: Applications can use the service to launch and control remote applications on the Terminal Server.
Remote Printing: Applications can use the service to manage and redirect print jobs to the Terminal Server or client machine.
It's worth noting that the TermSrv_API_service is typically only available on Windows systems that are running Remote Desktop Services or Terminal Server, and it requires that the appropriate permissions and credentials are set on the target machine. Additionally, vulnerabilities have been found in the past in the implementation of the TermSrv_API_service, that could be exploited by attackers to achieve remote code execution, denial of service and information disclosure.